Abstract:

An indirect estimation of nitrogen and potassium on experimental agrophysical fields for the two wheat varieties "Ester" and "Trizo" by mathematical analysis of the results of aircraft hyperspectral survey in the range from 450 to 900 nm is considered. After pre-processing of the received signals and performing external calibration (atmospheric correction) of image (conversion from signal space to the spectral brightness coefficients) nitrogen and potassium content is estimated by comparison of the remote data processing results with laboratory measurements of the percentage composition of the analyzed chemical elements in plant stems on test plots. Method of subpixel analysis is used for calculations where as reference are considered two middle spectrums calculated on the plots that corresponded to the maximal content of nitrogen and potassium. The quality of the result is controlled by comparing the concentrations of these substances and estimations of concentrations for those plots that are presented in the image herewith their spectral vectors are not used as reference. The results showed a significant dependence of the accuracy of the estimations on the type of probed culture.